2 concrete nails

If the zinc coating is good, but when the light comes out in 3% nitric acid, there is a dark shadow on the coating, and the film is brown when passivation occurs, which may be caused by foreign metal impurities such as copper or lead in the galvanized liquid. When there is a problem in the process of galvanizing, check the temperature and current density first, and then measure and adjust the content of zinc and sodium hydroxide in the bath through the analysis of the bath. Whether DPE levels are low can be determined by Hull cell test.

4, the material requirements of the silk: change wire braid, electric galvanized wire braid, hot galvanized wire braid, first braid after hot plating.

Non-proportional extension strength: It is mainly for hard steel without yield point. It is defined as the stress where the residual elongation of the standard distance part reaches 0.2% of the length of the original standard distance.